Forum & Topics pages – how to show the date of the last post ?

Hello,
On the Forum and on the Topics pages of an enfold-based site, I would like to know how to show the date of the last post.
It would be an easy way to see quickly if there’s recent posts on each forum and each topic.
Here’s the site but all the forums are private ones: http://www.oeil-arpenteur.org/blog/
Here’s is the screens of the forum and topics pages : https://www.flickr.com/photos/131367067@N06/
Thank you for your help.
Lionel